roof truss snow loads

[Hube]

What is the "safety factor" for a roof truss when it comes to snow load.
For instance, trusses that have been built to a "liveload" of say,47 psf, what amount of added weight could the roof take before danger of an collapse.

I imagine there must be a extra weight margin factor for any accumulated overload of snow, ice etc,, but does anyone know what it might be?

[ABP]

As a licensed carpenter I deal with manufactured trusses all the time and would have to say your best bet is to find out whome it was that manufactured your trusses and consult with them, as they are the only ones with the information needed to answer that question.